Question 1
Boil | Purifying Tablets | Portable filter/ Purifier | DIY Water Filter | Evaporation Trap | |
Cost | $0 | $8.59 for 100 | $20 | $0 | |
Effectiveness | Kills parasites, bacteria, germs | Availability limited | Time consuming depends on humidity. |
Question 2
Desalination techniques:
– thermal distillation
– membrane filtration
Reasons:
– Consumes a lot of energy -> costly
– Maintenance is high
– Damaged environment (sucks in small ocean creatures)
Question 3
Part A
Major Sources from:
– Lead pipes/compartment in plumbing
– Sediments in screens
– Lead parts
Part B
Unlikely due to:
– Proper bio-hazard waste disposal
– Drinking water comes straight from plant, not exposed to other sources
Question 4
Water-soluble |
Fat-soluble |
|
Vitamins | B, C | A,D,E,F |
Polarity | Polar | Non-polar |
Explanations | Energy released from interaction between polar vitamin and water molecules is sufficient to overcome hydrogen bonds. | Non polar molecules cannot disrupt hydrogen bonds between water molecules. |